未编组对象的文件中的 JAXB 位置

JAXB location in file for unmarshalled objects(未编组对象的文件中的 JAXB 位置)

问题描述

我有一些对象被 JAXB 从 XML 文件中解组.是否可以让 JAXB 告诉我或以某种方式找出每个对象在 XML 文件(行和列)中的位置?

I have some objects being unmarshalled from an XML file by JAXB. Is it possible to have JAXB tell me or somehow find out where in the XML file (line and column) each object comes from?

此信息在某些时候可用，因为 JAXB 在模式验证错误期间将其提供给我.但我也希望它可用于经过验证的对象.

This information is available at some point, because JAXB gives it to me during schema validation errors. But I would like to have it available for validated objects too.

推荐答案

您可以在 JAXB 中通过利用 XMLStreamReader 和 Unmarshaller.Listener 来做到这一点:

You could do this in JAXB by leveraging an XMLStreamReader and an Unmarshaller.Listener:

演示

package forum383861;

import java.io.FileInputStream;
import java.util.HashMap;
import java.util.Map;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Unmarshaller;
import javax.xml.bind.Unmarshaller.Listener;
import javax.xml.stream.Location;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamReader;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(Customer.class);


        XMLInputFactory xif = XMLInputFactory.newFactory();
        FileInputStream xml = new FileInputStream("src/forum383861/input.xml");
        XMLStreamReader xsr = xif.createXMLStreamReader(xml);

        Unmarshaller unmarshaller = jc.createUnmarshaller();
        LocationListener ll = new LocationListener(xsr);
        unmarshaller.setListener(ll);

        Customer customer = (Customer) unmarshaller.unmarshal(xsr);
        System.out.println(ll.getLocation(customer));
        System.out.println(ll.getLocation(customer.getAddress()));
    }

    private static class LocationListener extends Listener {

        private XMLStreamReader xsr;
        private Map<Object, Location> locations;

        public LocationListener(XMLStreamReader xsr) {
            this.xsr = xsr;
            this.locations = new HashMap<Object, Location>();
        }

        @Override
        public void beforeUnmarshal(Object target, Object parent) {
            locations.put(target, xsr.getLocation());
        }

        public Location getLocation(Object o) {
            return locations.get(o);
        }

    }

}

input.xml

<?xml version="1.0" encoding="UTF-8"?>
<customer>
    <address/>
</customer>

输出

[row,col {unknown-source}]: [2,1]
[row,col {unknown-source}]: [3,5]

客户

package forum383861;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class Customer {

    private Address address;

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }

}

地址

package forum383861;

public class Address {

}

更多信息

• http://blog.bdoughan.com/2011/08/using-unmarshallerlistener-to-capture.html

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